Finite element simulation for temperature field in Nd:YAG laser-TIG hybrid welding of 5A06 aluminium alloy

A heat source model of Nd: YAG laser-TIG hybrid welding has been established with the use of MSC.Marc, which combining the disc shaped weld heat source due to TIG and the Goldak's double ellipsoidal shaped weld heat source owing to laser. In order to consider the effects of laser-TIG hybrid on penetration depth grow, the factors in the model are introduced including heat flux gain of TIG, compressed factor of arc radius, heat flux gain of laser, penetration increasing ratio of laser. Experiments have been carried out by using 5A06 Aluminium Alloy. Comparison of penetration depth and weld width between experimental and simulation results shows that accuracy of the heat source. Simulations results show that: the heat flux of TIG and laser increases by 50% for TIG and laser enhances each other greatly, in which material absorptance to laser increases greatly coupled with TIG, and efficiency of TIG improves a lot companied with laser; arc radius of TIG is compressed to 2/3 with the compressing and attracting influence of laser on TIG; deeper key hole forms of laser due to arc's plasma dilution.